use getifaddrs from libc instead of private code

Reviewed by:	bms
MFC after:	1 month

1 files changed, 75 insertions, 147 deletions

diff --git a/sbin/ifconfig/ifconfig.c b/sbin/ifconfig/ifconfig.c
index 684bf9006828..3860bd5411e9 100644
--- a/sbin/ifconfig/ifconfig.c
+++ b/sbin/ifconfig/ifconfig.c
@@ -62,6 +62,7 @@ static const char rcsid[] =
 #include <arpa/inet.h>
 #include <netdb.h>
 
+#include <ifaddrs.h>
 #include <ctype.h>
 #include <err.h>
 #include <errno.h>
@@ -81,7 +82,6 @@ static const char rcsid[] =
 struct	ifreq ifr;
 
 char	name[IFNAMSIZ];
-int	flags;
 int	setaddr;
 int	setipdst;
 int	setmask;
@@ -94,9 +94,8 @@ int	supmedia = 0;
 int	printkeys = 0;		/* Print keying material for interfaces. */
 
 static	int ifconfig(int argc, char *const *argv, const struct afswtch *afp);
-static	void status(const struct afswtch *afp, int addrcount,
-		    struct sockaddr_dl *sdl, struct if_msghdr *ifm,
-		    struct ifa_msghdr *ifam);
+static	void status(const struct afswtch *afp, const struct sockaddr_dl *sdl,
+		struct ifaddrs *ifa);
 static	void tunnel_status(int s);
 static	void usage(void);
 
@@ -141,16 +140,13 @@ int
 main(int argc, char *argv[])
 {
 	int c, all, namesonly, downonly, uponly;
-	int need_nl = 0, count = 0;
 	const struct afswtch *afp = NULL;
-	int addrcount, ifindex;
-	struct if_msghdr *ifm, *nextifm;
-	struct ifa_msghdr *ifam;
-	struct sockaddr_dl *sdl;
-	char *buf, *lim, *next;
-	size_t needed;
-	int mib[6];
-	char options[1024];
+	int ifindex;
+	struct ifaddrs *ifap, *ifa;
+	struct ifreq paifr;
+	const struct sockaddr_dl *sdl;
+	char options[1024], *cp;
+	const char *ifname;
 	struct option *p;
 
 	all = downonly = uponly = namesonly = verbose = 0;
@@ -213,6 +209,7 @@ main(int argc, char *argv[])
 		if (argc > 1)
 			usage();
 
+		ifname = NULL;
 		ifindex = 0;
 		if (argc == 1) {
 			afp = af_getbyname(*argv);
@@ -227,13 +224,13 @@ main(int argc, char *argv[])
 		if (argc < 1)
 			usage();
 
-		strncpy(name, *argv, sizeof(name));
+		ifname = *argv;
 		argc--, argv++;
 
 		/* check and maybe load support for this interface */
-		ifmaybeload(name);
+		ifmaybeload(ifname);
 
-		ifindex = if_nametoindex(name);
+		ifindex = if_nametoindex(ifname);
 		if (ifindex == 0) {
 			/*
 			 * NOTE:  We must special-case the `create' command
@@ -245,7 +242,7 @@ main(int argc, char *argv[])
 				ifconfig(argc, argv, NULL);
 				exit(0);
 			}
-			errx(1, "interface %s does not exist", name);
+			errx(1, "interface %s does not exist", ifname);
 		}
 	}
 
@@ -256,106 +253,55 @@ main(int argc, char *argv[])
 			argc--, argv++;
 	}
 
-retry:
-	mib[0] = CTL_NET;
-	mib[1] = PF_ROUTE;
-	mib[2] = 0;
-	mib[3] = 0;			/* address family */
-	mib[4] = NET_RT_IFLIST;
-	mib[5] = ifindex;		/* interface index */
-
-	/* if particular family specified, only ask about it */
-	if (afp != NULL)
-		mib[3] = afp->af_af;
-
-	if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
-		errx(1, "iflist-sysctl-estimate");
-	if ((buf = malloc(needed)) == NULL)
-		errx(1, "malloc");
-	if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
-		if (errno == ENOMEM && count++ < 10) {
-			warnx("Routing table grew, retrying");
-			free(buf);
-			sleep(1);
-			goto retry;
-		}
-		errx(1, "actual retrieval of interface table");
-	}
-	lim = buf + needed;
-
-	next = buf;
-	while (next < lim) {
-
-		ifm = (struct if_msghdr *)next;
-		
-		if (ifm->ifm_type == RTM_IFINFO) {
-			if (ifm->ifm_data.ifi_datalen == 0)
-				ifm->ifm_data.ifi_datalen = sizeof(struct if_data);
-			sdl = (struct sockaddr_dl *)((char *)ifm + sizeof(struct if_msghdr) -
-			     sizeof(struct if_data) + ifm->ifm_data.ifi_datalen);
-			flags = ifm->ifm_flags;
-		} else {
-			fprintf(stderr, "out of sync parsing NET_RT_IFLIST\n");
-			fprintf(stderr, "expected %d, got %d\n", RTM_IFINFO,
-				ifm->ifm_type);
-			fprintf(stderr, "msglen = %d\n", ifm->ifm_msglen);
-			fprintf(stderr, "buf:%p, next:%p, lim:%p\n", buf, next,
-				lim);
-			exit (1);
+	if (getifaddrs(&ifap) != 0)
+		err(EXIT_FAILURE, "getifaddrs");
+	cp = NULL;
+	ifindex = 0;
+	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
+		memset(&paifr, 0, sizeof(paifr));
+		strncpy(paifr.ifr_name, ifa->ifa_name, sizeof(paifr.ifr_name));
+		if (sizeof(paifr.ifr_addr) >= ifa->ifa_addr->sa_len) {
+			memcpy(&paifr.ifr_addr, ifa->ifa_addr,
+			    ifa->ifa_addr->sa_len);
 		}
 
-		next += ifm->ifm_msglen;
-		ifam = NULL;
-		addrcount = 0;
-		while (next < lim) {
-
-			nextifm = (struct if_msghdr *)next;
-
-			if (nextifm->ifm_type != RTM_NEWADDR)
-				break;
-
-			if (ifam == NULL)
-				ifam = (struct ifa_msghdr *)nextifm;
+		if (ifname != NULL && strcmp(ifname, ifa->ifa_name) != 0)
+			continue;
+		if (ifa->ifa_addr->sa_family == AF_LINK)
+			sdl = (const struct sockaddr_dl *) ifa->ifa_addr;
+		else
+			sdl = NULL;
+		if (cp != NULL && strcmp(cp, ifa->ifa_name) == 0)
+			continue;
+		if (strlcpy(name, ifa->ifa_name, sizeof(name)) >= sizeof(name))
+			continue;
+		cp = ifa->ifa_name;
 
-			addrcount++;
-			next += nextifm->ifm_msglen;
-		}
-		memcpy(name, sdl->sdl_data,
-		    sizeof(name) <= sdl->sdl_nlen ?
-		    sizeof(name)-1 : sdl->sdl_nlen);
-		name[sizeof(name) <= sdl->sdl_nlen ?
-		    sizeof(name)-1 : sdl->sdl_nlen] = '\0';
-
-		if (all || namesonly) {
-			if (uponly)
-				if ((flags & IFF_UP) == 0)
-					continue; /* not up */
-			if (downonly)
-				if (flags & IFF_UP)
-					continue; /* not down */
-			if (namesonly) {
-				if (afp == NULL || afp->af_af != AF_LINK ||
-				    sdl->sdl_type == IFT_ETHER) {
-					if (need_nl)
-						putchar(' ');
-					fputs(name, stdout);
-					need_nl++;
-				}
-				continue;
-			}
+		if (downonly && (ifa->ifa_flags & IFF_UP) != 0)
+			continue;
+		if (uponly && (ifa->ifa_flags & IFF_UP) == 0)
+			continue;
+		ifindex++;
+		/*
+		 * Are we just listing the interfaces?
+		 */
+		if (namesonly) {
+			if (ifindex > 1)
+				printf(" ");
+			fputs(name, stdout);
+			continue;
 		}
 
 		if (argc > 0)
 			ifconfig(argc, argv, afp);
 		else
-			status(afp, addrcount, sdl, ifm, ifam);
+			status(afp, sdl, ifa);
 	}
-	free(buf);
-
-	if (namesonly && need_nl > 0)
-		putchar('\n');
+	if (namesonly)
+		printf("\n");
+	freeifaddrs(ifap);
 
-	exit (0);
+	exit(0);
 }
 
 static struct afswtch *afs = NULL;
@@ -698,6 +644,7 @@ static void
 setifflags(const char *vname, int value, int s, const struct afswtch *afp)
 {
 	struct ifreq		my_ifr;
+	int flags;
 
 	bcopy((char *)&ifr, (char *)&my_ifr, sizeof(struct ifreq));
 
@@ -722,6 +669,7 @@ setifflags(const char *vname, int value, int s, const struct afswtch *afp)
 void
 setifcap(const char *vname, int value, int s, const struct afswtch *afp)
 {
+	int flags;
 
  	if (ioctl(s, SIOCGIFCAP, (caddr_t)&ifr) < 0) {
  		Perror("ioctl (SIOCGIFCAP)");
@@ -780,25 +728,6 @@ setifname(const char *val, int dummy __unused, int s,
 	free(newname);
 }
 
-/*
- * Expand the compacted form of addresses as returned via the
- * configuration read via sysctl().
- */
-static void
-rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo)
-{
-	struct sockaddr *sa;
-	int i;
-
-	memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
-	for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
-		if ((rtinfo->rti_addrs & (1 << i)) == 0)
-			continue;
-		rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
-		cp += SA_SIZE(sa);
-	}
-}
-
 #define	IFFBITS \
 "\020\1UP\2BROADCAST\3DEBUG\4LOOPBACK\5POINTOPOINT\6SMART\7RUNNING" \
 "\10NOARP\11PROMISC\12ALLMULTI\13OACTIVE\14SIMPLEX\15LINK0\16LINK1\17LINK2" \
@@ -813,10 +742,10 @@ rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo)
  * specified, show only it; otherwise, show them all.
  */
 static void
-status(const struct afswtch *afp, int addrcount, struct	sockaddr_dl *sdl,
-    struct if_msghdr *ifm, struct ifa_msghdr *ifam)
+status(const struct afswtch *afp, const struct sockaddr_dl *sdl,
+	struct ifaddrs *ifa)
 {
-	struct	rt_addrinfo info;
+	struct ifaddrs *ift;
 	int allfamilies, s;
 	struct ifstat ifs;
 
@@ -834,11 +763,11 @@ status(const struct afswtch *afp, int addrcount, struct	sockaddr_dl *sdl,
 		err(1, "socket(family %u,SOCK_DGRAM)", ifr.ifr_addr.sa_family);
 
 	printf("%s: ", name);
-	printb("flags", flags, IFFBITS);
-	if (ifm->ifm_data.ifi_metric)
-		printf(" metric %ld", ifm->ifm_data.ifi_metric);
-	if (ifm->ifm_data.ifi_mtu)
-		printf(" mtu %ld", ifm->ifm_data.ifi_mtu);
+	printb("flags", ifa->ifa_flags, IFFBITS);
+	if (ioctl(s, SIOCGIFMETRIC, &ifr) != -1)
+		printf(" metric %d", ifr.ifr_metric);
+	if (ioctl(s, SIOCGIFMTU, &ifr) != -1)
+		printf(" mtu %d", ifr.ifr_mtu);
 	putchar('\n');
 
 	if (ioctl(s, SIOCGIFCAP, (caddr_t)&ifr) == 0) {
@@ -854,22 +783,20 @@ status(const struct afswtch *afp, int addrcount, struct	sockaddr_dl *sdl,
 
 	tunnel_status(s);
 
-	while (addrcount > 0) {
-		info.rti_addrs = ifam->ifam_addrs;
-		/* Expand the compacted addresses */
-		rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
-			  &info);
-
+	for (ift = ifa; ift != NULL; ift = ift->ifa_next) {
+		if (ift->ifa_addr == NULL)
+			continue;
+		if (strcmp(ifa->ifa_name, ift->ifa_name) != 0)
+			continue;
 		if (allfamilies) {
 			const struct afswtch *p;
-			p = af_getbyfamily(info.rti_info[RTAX_IFA]->sa_family);
+			p = af_getbyfamily(ift->ifa_addr->sa_family);
 			if (p != NULL && p->af_status != NULL)
-				p->af_status(s, &info);
-		} else if (afp->af_af == info.rti_info[RTAX_IFA]->sa_family)
-			afp->af_status(s, &info);
-		addrcount--;
-		ifam = (struct ifa_msghdr *)((char *)ifam + ifam->ifam_msglen);
+				p->af_status(s, ift);
+		} else if (afp->af_af == ift->ifa_addr->sa_family)
+			afp->af_status(s, ift);
 	}
+#if 0
 	if (allfamilies || afp->af_af == AF_LINK) {
 		const struct afswtch *lafp;
 
@@ -885,6 +812,7 @@ status(const struct afswtch *afp, int addrcount, struct	sockaddr_dl *sdl,
 			lafp->af_status(s, &info);
 		}
 	}
+#endif
 	if (allfamilies)
 		af_other_status(s);
 	else if (afp->af_other_status != NULL)
@@ -954,7 +882,7 @@ printb(const char *s, unsigned v, const char *bits)
 }
 
 void
-ifmaybeload(char *name)
+ifmaybeload(const char *name)
 {
 	struct module_stat mstat;
 	int fileid, modid;